In this diagram you can see the potential difference across the battery and resi

Question

In this diagram you can see the potential difference across the battery and resistor is the same as the pd created by the battery (the battery and resistor are representing a battery with internal resistance):
enter image description here

I know the route through the voltmeter is not actually a route, so I'm guessing here is no current? But why* is there no difference in the voltmeter reading, whether you put the voltmeter across the battery and resistor or just the battery?

The following diagram makes sense to me as some pd should be dropped over the internal resistance (the 680ohm resistor):
enter image description here

*(physically, when I put the numbers into the equations it make sense mathematically, but I don't understand the physics side)

Explanation / Answer

The resistance through the voltmeter is so much greater than that of the resistor that the resistor's resistance has negligible impact on the circuit. A precise-enough voltmeter would see a very small difference, on the order of micro or nanovolts.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.